Shielded telephone plug



Aug. 2 2, l939.` c. w.. D`oREMUs v.2,170,131

SHIELDED TELEPHONE 4PLU@ FiledJuly 2, 1938 Hnnnnnnnnnnnnl' l INVENTORCORNELIUS W. DOREMUS ATTORNEY Patented Aug. 22, 1939 UNITED STATESZiltdl rATENT orricr 4 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) This invention relates to a shielded telephone plug, and hasfor an object to provide a practically indestructible rubber coveredtelephone plug which can be manufactured more economically and will haveafar longer useful life than the present known type of breakabletelephone plugs. z

A further objectof this invention is to provide a telephone plug havingits'body made preferably of soft molded rubber, which hence cannot beeasily broken, and, further which is provided with an efficientgrounding medium for a shielded telephone cord, which grounding mediumserves as a cord tie bracketwhen used with an unshielded telephone cord.

With the foregoing and other objects in view, the invention consists inthe construction, combination and arrangement of parts hereinafterdescribed and illustrated in the drawing, in which,

Fig, l is a longitudinal sectional view of the plug of this invention online I-I of Fig. 3;

Fig. 2 is a longitudinal sectional view at right angles to the View ofFig. 1, being on line 2-2 of Fig. 3; and

Fig. 3 is an end View of the telephone plug.

There is shown at I the telephone plug of this invention, which includesa stem Il, preferably made of brass, and having a ball head tip I2 atone end thereof, and is threaded as at I3 at its other end, whereby itis secured in a terminal I4. Surrounding the stem II is a barrel I5,likewise of brass. This barrel I5 is separated from Vthe stem I I bymeans of an insulating sleeve I6, preferably of rubber, and from theball head I2 by means of an insulating washer I 1. The other end of thebarrel I5 is provided with a shoulder I8 separating it from an enlargedtrunk I9, which finally ends at one side in a terminal 2D. The

trunk I9 is provided with a pair of recessed` grooves 2|. The trunk I9is separated from the terminal I4 by rubber insulation 22 and thetermina] I4 is similarly separated from the terminal Z by rubberinsulation 23.

A rubber body 24 of semi-soft rubber is molded about the trunk I9 andterminals I4 and 20, being anchored thereto by the recessed grooves 2 I.Embedded in the rubber body 24 is a grounding spring 25 shaped somewhatin the form of a Y, having its Y stem 26 extending at the end of thebody 24 and formed into an eyelet 2'I. The ends of the Y legs extendoutwardly of the cylindrical body 24 as at 28, having their tips 29curved back into the body as shown, the body being cut away in anaperture 30 under the ends 28.

The terminals I4 and 20 are each provided with female plug receivingrecesses 3|, access to which are had for the telephone cord terminaltips by means of cylindrical passages 32 connecting thereto. Each femaleterminal 3l has a threaded aperture 33 extending through a side 6thereof for reception of a terminal holding screw which may beiinsertedand countersunk through apertures 34 in the side of the body 24.

In operation, the parts of the telephone plug are assembled as abovedescribed. If used With l0 a shielded telephone cord, the shielding isconnected to the eyelet 2T of the grounding spring 25. The plug lil isplaced in its jack in the usual manner with the sleeve l5 and ball headI2 serving as contacts as conventional, the shoulder I8 15 limiting theentrance ofthe plug into the jack to just the predetermined amount andlikewise making a click sound as the plug is pushed home into the jack,thereby informing the user that the plug is properly in position withinthe jack. 20

The yieldable ends 28 of the grounding spring 25 make contacts with asuitably positioned grounding portion of the jack, and thus ground theshield of the shielded wire, preventing stray electrical impulses frominterfering with the 25 proper operation.

If used with an ordinary unshielded telephone cord, the eyelet 2l servesas a cord tie bracket to prevent the telephone tips from beingaccidentally withdrawn from the terminals I4 and 2U. The 30 telephone ofthis invention thus serves interchangeably for both shielded orunshielded telephone cords, and furthermore, will stand up under extremeservice conditions, inasmuch as it has no easily frangible parts. 35

Other modifications and changes in the proportions and arrangements ofthe parts may be made by those skilledv in the art without departn ingfrom the nature of the invention, within the scope of what ishereinafter claimed.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

Having thus set forth and disclosed the nature of this invention, whatis claimed is:

l. A telephone cord plug comprising a stem contact and a barrel Contactencompassing said stem contact, an insulating sleeve between said barrelcontact and said stem contact, an enlarged trunk extending from saidbarrel Contact and a cord tip-receiving terminal extending from one sideof said trunk, a second cord tipweceiving terminal, said stem beingsecured to said second terminal, insulating means separating said secondterminal from said trunk and said rst terminal, a shoulder dividing saidtrunk from said barrel to limit the amount that the plug may be insertedin a jack, and a yieldable insulating material molded about said trunkand terminals in situ and having apertures allowing insertion of cordtips into said cord tip-receiving terminals, said trunk having aplurality of grooves thereabout to anchor the molded insulating materialthereon, said molded insulating material comprising semi-soft rubber.

2. A telephone cord plug comprising a stem Contact and a barrel Contactencompassing said stem contact, an insulating sleeve between said barrelcontact and said stem contact, an enlarged trunk extending from saidbarrel contact and a cord tip-receiving terminal extending from one sideof said trunk, a second cord tip-receiving terminal, said stem beingsecured to said second terminal, insulating means separating said secondterminal from said trunk and said first terminal, a yieldable insulatingmaterial molded about said trunk and terminals in situ and` havingapertures allowing insertion of cord tips into said cord tip-receivingterminals, and a cord shield grounding means extending through saidmolded insulating material,

3. A telephone cord plug comprising a stern contact and a barrel contactencompassing'said stem contact, an insulating sleeve between said barrelContact and said stem Contact, an enlarged trunk extending from saidbarrel Contact and a cord tip-receiving terminal extending from one sideof said trunk, a second cord tip-receiving terminal, said stem beingsecured to said second terminal, insulating means separating said secondterminal from said trunk and said rst terminal, a yeldable insulatingmaterial molded about said trunk and terminals and having aperturesallowing insertion of cord tips into said cord tip-receiving terminals,a cord shield grounding means extending through said molded insulatingmaterial, said grounding means having an eyelet extending through an endof the molded insulating material for connection to a'shield to begrounded, and a yieldable portion extending through a side of theinsulating material to ground the same.

4. A telephone cord plug comprising a stem Contact and a barrel contactencompassing said stem contact, an insulating sleeve between said barrelcontact and said stem contact, an enlarged trunk extending from saidbarrel contact and a cord tip-receiving terminal extending from one sideof said trunk, a second cord tipreceiving terminal, said stem beingsecured to said second terminal, insulating means separating said secondterminal from said trunk and said first terminal, a yieldable insulatingmaterial molded about said trunk and terminals in situ and havingapertures allowing insertion of cory tips into said cord tip-receivingterminals, a cord shield grounding means extending through said molded`insulating material, said grounding means comprising a Y shaped springhaving its Y legs extending outwardly through opposite sides of themolded insulating material and having its tips turned back inwardly tothe material again to provide yieldable grounding contacts. Y

CORNELIUS W. DOREMUS.

